1. Field of the Invention
The present invention relates to an airbag for a front passenger's seat of vehicle that is mounted on a top area of an instrument panel in front of a front passenger's seat and is deployable upward and rearward in such a manner as to fill in a space between the top of the instrument panel and a windshield.
2. Description of Related Art
As known in JP 2006-103654, for example, a conventional airbag for a front passenger's seat is made by joining a pair of outer panels that constitute laterals of the airbag and a pair of generally C-shaped inner panels that are located in an inner area in the transverse direction of the airbag such that it inflates into a generally square conical shape whose front end is the top of the square cone. The airbag internally includes at a center in the transverse direction at full inflation a communication port defined by an inner joint that joins inner circumferential edges of the inner panels together. The airbag includes at least on a rear area corresponding to the circumferential edge of the communication port at full inflation a recess that recesses forward and a pair of raised regions that project rearward relative to the recess on the left and right of the recess and each extend generally vertically. In operation, when a vehicle occupant contacts the airbag, the airbag firstly arrests shoulders of the occupant by the raised regions and then softly receives a head of the occupant whose kinetic energy has been reduced by the arrest of the shoulders by the recess.
The above conventional airbag still have a room for improvement especially in the protection of an occupant seated excessively proximate the dashboard (known as an Out-of-Position occupant) because there is a potential risk that an area of the airbag around the communication port may contact and unduly press such occupant before the raised regions deploy enough rearward to arrest his/her shoulders.
JP 2004-502585 discloses an airbag designed to reduce a risk to the Out-of-Position occupant. The airbag includes at a center in the transverse direction of the rear side at full inflation a recess that recesses forward and a pair of raised regions located on the left and right of the recess. The raised regions separate from each other in an opening manner when contacting an Out-of-Position occupant such that the recess receives the occupant between the raised regions.
However, the raised regions must be kept contacting each other if the airbag is used to protect an occupant seated at a normal position. The above airbag includes means for keeping the raised regions closed such as a wrapping member, but this means complicates the structure of the airbag.